This table lists the earliest sightings of resident and regular migrant butterfly species in 2017 reported to Butterfly Conservation HQ and Nick Bowles.

These first sightings are gathered as the butterfly season progresses so as to provide up-to-date information about species emergence. They are not reviewed retrospectively by reference to transect data or distribution records and therefore represent what we believed to be the first report of a species at the time rather than a comprehensive analysis of the actual first dates recorded in a particular year.